Process of treating oils



C. P. DUBBS.

PROCESS OF TREATING OILS.

APPLICATION FIILED APR. 16, 1911.

Patented Apr. 4, 19222 3% W \4 SHEETS-SHEET I.

C. P. DUBBS.

PROCESS OF TREATING OILS.

APPLICATION FILED APR 16. 1917.

2 92 1 b i new p AH. d 11! w 9w 1 4 w z I J m A m I 1 \||||1 L x n 7 I l] I I ILQIZF w m 5 x 1 v 6 M fl 1 6 2 c. P. DUBBS. PROCESS OF TREATING OILS.

APPLICATION FILED APR 16, I917.

Patented Apr. 4, 1922.

4 SHEETSQSHEET 3.

C. P. DUBBS.

PROCESS OF TREATING OILS.

APPLICATION FILED APR. 16. 1917.

1,41 1,961. Patented Apr. 4, 1922.

4 SHEETS-SHEET 4- 1 UNITED STATES PATENT OFFICE.

CARBON I. DUBBS, OF WILMETTE, ILLINOIS, ASSIGNOR TO UNIVERSAL OIL PRODUCTS COMPANY, OF CHICAGO, ILLINolS A CORPORATION OF SOUTH DAKOTA.

PROCESS OF TREATING OILS.

Specification of Letters Patent.

Patented Apr. 4, 1922.

Application filed April 16, 1917. Serial No. 162,233.

I '0 all whom it may concern:

useful Improvements in Processes of Treating Oils, of which the following is a specification.

The art of cracking petroleum hydrocarbons to form light hydrocarbons has become exceedingly active in the last few years. This is due primarily to commercial necessities confronting oil refiners. The constantly and rapidly increasing consumption of gasoline, the fact that the production of crude petroleum oil has not increased proportionately, the relatively high prices obtained for gasoline and the relatively low prices obtained for the other refined products, coupled with the increasing price of crude oil has forced the oil refiners, particularly the so-called independent refiners to be constantly striving to find some process which will commercially convert the heavier hydrocarbons into lighter hydrocarbons, particularly those of the gasoline series.

The most successful attempts so far to produce the desired result have been by pressure processes in which pressure is. maintained on both the still and the condenser by means of the generated vapors. The present invention is an improvement on processcs of this character.

Among the salient objects of the present invention are to provide a process in which the oil is circulated through the heated zone so as to subject it to the action of uniform heating for a maximum period of time, while, at the same time, permitting the va pors to pass freely to the condenser; to provide a process in which the danger due 'to local overheating arising from carbon deposits in the apparatus is obviated by causing the carbon to be precipitated and deposited at points remote from and outsideof the heated zone of the combustion gases to provide a process which can be run either as a continuous process or as a batch proccss and if desired, in the same apparatus;

to provide a process in which a relatively rapid circulation of the oil through the heating zone is obtained, preferably ,by convection; to provide a process in which the partially qconverted vapors are condensed and returned to the heating zone; to

provide a process in which the incoming fresh oil is preferably preheated by means of the outgoing vapors acting in effect as ,a heat interchanger; to provide a novel apparatus for carrying out the improved process and in general to provide an improved process and apparatus of the character referred to.

In the drawings: Fig. l is a side elevation of my improved apparatus suitable vfor carrying out the process.

Fig. 2 is a side elevation of the still on an.

enlarged scale with parts broken away and shown 1n sectlon to bring out details of construction.

Fig. 3 is a side elevation of the front end of any suitable number and are preferably of the horizontal boiler type. 5 designates the furnace of any suitable construction, within which is mounted the still proper designated as a whole 6. This still or retort consists of a cylindrical upper drum or receiver 7 and a pair of lower drums 8 and 9, the upper and lower 'dru'ms being connected by means of tubes 10, which are fitted in suitable heads in the drums in a well known manner. The tubes which extend into the drum 8 aresep'arated from the tubes leading to the drum 9, by a fire arch or bridge wall 11. The arrangement is such that the gases of combustion from the fire box of the furnace 5 are compelled to. pass up over the bridgewall and down to the bottom of the sstack 12. The stack is controlled by suitable dampers 13. The lower drums 8 and 9 are provided withhand hold plates 14, so that they can be cleaned out and the upper drum? is provided with a similar hand hold plate 15. The upper drum 7 also is provided with a gauge 16, liquid gauge 17 and safetyvalve 18. On the upper end of the drum 7 is mounted a combined reflux condenser and heat interchanger 19. The member 19 consists of upper and lower headers 20 and 21 connected by tubes 22, through which the vapors pass, the lower header 21 being connected by pipe 23 to the drum 7. The headers are surrounded with a shell 24. Incoming crude oil is admitted to the chamber 24through the supply pipe near the lowerend of the chamber and is taken out near the upper end of the chamber through pipe 26. The pipe 22 leads to a pump 27, which is connected through pipe 28 to any suitable source of supply such as an oil line or oil tank. The delivery pipe 26 leads to the manifold 29, which is connected by means of branch pipes 30 to the front ends of the receiving drums 1, 2, 3 and 4. A valve 31 is interposed in the feed line 26 and similarly the branch feed pipes 30 are each provided with a valve 32 so that any one or more of the drums can be cut out of the feed line.

The'oil may be delivered from the bulk supply or receiving drums through the retort either by taking the oil out of the top of the drums or out of the bottom of the drums. Describing first the manner of taking the oil out of the top of the drums which can be done in the event that the process is operated as a continuous pI0C8SS, 1. e.. with a. constant supply of fresh oil being fed to the drum a pipe 33 leads from the top of each drum and connects to manifold pipe 34, which is in turn connected to the lower end of the drum 8, through pipes 35 and 36. Describing the manner in which the oil is taken from the lower end of the supply drums and delivered to the retort. which must be done in the event the process is operated as a batch process, pipes 37 extend down into each drum near the bottom as shown more clearly in Fig. 1 and are connected to the-manifold 34 and thus lead to the drum 8 through the same pipes 35 and 36. The pipes 33 are provided with valves 38 and the pipes 37 are similarly provided with valves 39, it being obvious that when the valves of the pipes 33 are open, the valves of the pipe 37 are closed, and vice versa.

Describing now the manner in which the oil is circulated fromthe retort back to the drums, a return pipe 40 connects to a return manifold 41, and from this manifold 41 return pipes 42 lead to the front end of the drums 1, 2, 3 and 4. Valves 43 are interposed in the return pipes 42 whereby any pipe may be cut out. From the foregoing it will be seen that whether the oil is taken from the top or bottom of the sup-ply drums,

1, 2, 3 and 4, it is circulated from the supply tank through the drum 8, tube 10, drum 7, tube 10, drum 9 and back to the supply tanks through the by-way of the manifold 41 and return pipes 42. From the foregoing it will also be seen that the supply tanks are connected in multiple.

When the process is operated as a continuous process, means must be provided for continuously removing theheavy residuum from the supply drums 1, 2, 3 and 4. This is accomplished by means of the header 44, which is connected to the rear ends of the drums about midway their height by means of bralich pipes 45, controlled by valves 46, 47 and 48. The object of having the triple sets of valves is that by shutting the valves 46 and 48 on any supply drum and opening the valve 47, on said supply drum, this supply drum is cut out and by-passed. By opening the valves 46 and 48 and closing the valve 47 the supply drum is admitted into the series.

In certain instances, it may be desirable to connect the supply tanks in series instead of in multiple so as to form in effect, one large supply tank. This is accomplished as follows: The valves 43 in the pipes 42 lead ing to drums 1, 2, and 3 are shut. The valve 43 in the pipe 42 leading to drum 4 is left 0 )en. Valves 46 and 47 on drum 4 are closed. alve 48 on drums 4 is left open. Valves 46 and 48 on drums 2 and 3 are left open while valves 47 in drums 2 and 3 are closed. Valve 46 in drum 1 is left open while valves 47 and 48 are closed. The circulation is then as follows:

The oil is introduced from suction line 28 to pump 27 and discharged through line 22 into and through reflux condenser 19 and withdrawn from there through line 26. Thence the oil passes into manifold 29 and by branch pipes 30 to the front end of the receiving drums. The oil is drawn from these drums (or as many of them as are then open into the system) through pipes 33 (if a continuous process is being used) or pipes 37 (if a batch process is being used) to manifold 34 and back by pipes 35 and 36 to bottom of drum 8. From drum 8 oil fiows through the tubes to the drum 7 and then back through the adjacent tubes to drum 9. From drum 9, the oil goes through outlet 40, to manifold 41 and back to the su aply drums.

Vhere the processis operated as a continuous one. the drums 1 and 2, 3 and 4 are kept practically full. To prevent the gas I pocket which is usually formed in the drums,

each is rovided with. an outlet 49, leading to mani old 50, each pipe 49 having a valve 51. The manifold 50 leads to any suitable storage.

From the top of the header 20 of the reflux condenser. a pipe 52 leads to a water condenser 53, the latter being mounted in a suitable water tank 54. The coils of the condenser 53 are so positioned as to have a gradual incline downwardly to the receiving'tank' 55. \Vater is supplied to the tank 54 by means of supply pipe 56 having a valve 57. Theta-11k 54 also has a water overflow'pipe 58. In thep'ipe v52 is interposed valve 59. The receiving tank 55 has a safety valve 60, pressure gauge 61, glass liquid gauge 62, and gas blowofi' pipe 63, controlled by valve 64. The lower end of'the receiving tank 55 has a distillate discharge line, 65, controlled by valve 66. Preferably. a Water drawofi' 67 is provided having a valve 68. From the foregoing it will be seen that pressure can be maintained on both the still and condenser and regulated by means of valves 64 and 66; at the start of the process, to get up initial pressure, the valve 59 may be closed. The reflux condenser is provided with pressure gauge 69 and the pipe .52 with a pyrometer 70. The receiving tanks are also provided with water gauges 71, to

show the level of the liquid in the drums.

The operation of the process is'as follows: Oil, whether .it be" crude petroleum, distillate or residuum is pumped into the receiving drums which are connected either in multiple or in. series as, may be desired in sufiicient quantity to fill the latter up to the level designated by line A in the drum 7.

. As the oil in the retort is heated, the vapors is subject tively prolonged periods.

will pass up through the reflux'condenser and thence over into tthe receiving tank through the gooseneck and water condenser. The heavier or partially converted vapors will be condensed in their passage through the reflux condenser and will fall back into the retort and be again subjected to the cracking action. The incoming crude oil acts as a condenser to return these heavier vapors to the retort. If the process is operated as a batch process the reflux condenser can either be used as an aerial condenser or it can be cooled in some other suitable manner. The unvaporized oil which passes through the retort is, of course, returned to the drum and again delivered to the retort and can be subjected to the heat of the cracking action.

In practice, this circulation takes lace very rapidly so that the oil to the heating action for rela- The receiving tanks are preferably insulated and the c1r-. culation is so rapid that the oil in passing from the lower end of the retort back to the drums is only slightly cooled. It is necessary that it be cooled somewhat in order to get a rapid circulation. The temperature and pressure varies with the character of the oil being treated. A temperature of from 450 to 1000 F. is suitable and a pressure of Y from 80 to 250 pounds to the square inch will probably be ample.

As will be appreciated by those skilled; in this art, there Wlll be formed in the-oil under "treatment in the heating tubes numerous carbonaceous particles, insoluble inthe oil in whichthey are formed and of heavier gravity thanthe oil, which have a tendency to adhere to any metalllc surfaces with which they may contact, 'and the adhering of these-particles to the walls of the heat ing tubes seriously militates against the ef- I ficient operation of the apparatus;

In my described processth'is detrimental action is obviated, or greatly lessened. These carbonaceous particles in carrying out my' process tend to move in a direction substantially. parallel. with the walls of the heating tubes, and there is thus no chance for v the particles to settle upon such surfaces, as;

occurs when the heating tubes are hori.-' zontally arranged, or arranged approximately in a horizontal position. Moreover, the sweep of the oil through the tubes tend to prevent the adherence of the the walls of the tube.

In my process, as hereinbefore described,

particles to v certain of the carbonaceous particles will be. 1

carried along by the upward flowing streams of oil in the front batteryof tubes, and a 1 majorityof such particles'will be deposited in the upper header, or drum 7, about the. ends of the tubes. The other particles'sepr arated from. the oil in the heating thereof will for the most part find lodgment in the lower drums 8 and 9.

In my process, as hereinbefore described,

the movement of thevapors generated inthereof, discharging the heated oil from the i upper ends of the tubes into a relatively large receiver. having a vapor space above .the level of the oil therein, taking off from the receiver the products of vaporization, controlling the discharge ofthe latter for imposing a substantial pressure on the oil under treatment, and returning to the lower ends of the tubes from the receiver the unvaporized oil for further heating in said tubes. 1

2. The described process for cracking oil, consisting in effecting by convection the passage upwardly in a battery of substantially vertically disposed tubes of a part of a body of oil, during which the temperature of the oil is. raised sufficiently to "crack a substantial part thereof, discharging the heated oil from the upper ends of thetubes into a relatively large receiver having a vapor space above the level of the oil therein, taking off from the receiver the products of vaporization, controlling the discharge of the latter for imposing a substantial prestion located in a sure on the oil under treatment, and'returning to the lower ends of the tubes from the receiver the unvaporized oil for further it is heated to cause cracking, taking off the generated vapors from above said pool,

and controlling the discharge of the vapors for maintaining a substantial, pressure on the-body of oil under treatment.

4. The described pressure process for cracking oil, consisting in maintaining a body of oil, with a portion located in a battery of vertical tubes, a portion arranged as a pool in free communication with the upper ends of the tubes, and a portion located between the pool'and lower ends of the tubes, efiecting a cyclic circulation of said oil to cause the same in relatively small portions to flow upwardly through said tubes, wherein it isheated to a temperature between 400 to-1000 F., taking off from the oil in the pool the generated vapors, condensing the condensi le portions thereof, and controlling the discharge of the vapors for producing a pressure thereof upon the p 3 the i n q I I which consists in providing a body of 011.

body of oil between 80 to 250 pounds to V sr iuare inch. 1 i 5', he described process for cracking Oll,

. ,with" a relatively small portion thereof held ,in ga battery of vertical tubes, located in aheating zone, a second portion held 1n :1 second batte of tubes, located in said heating zone and more remote from the source of heat thanthe'firstbattery, another portion of said body of oil being held as a pool above and :in open communication with the two batteries of tjnbes,and having avapor space above the same, and an additional portion located between and in open communication with the lower ends of the two -hatteriesof tubes, said body of oil being given acyclic circulation upwardl in rel'atively' small quantities through t e tubes of the first battery and downwardly through I the tubes of the second battery, andthe generated *vapors being taken off from 'said' pounds tothe vapor space and condensed, and the discharge thereof controlled for imposing a pressure of the-{generated vapors'upon the 011 under treatment.

6. Thedescribed process which consists iniprovidinga body ofoil with a relatively small portlon thereof held.

for cracking oil,

source of heat than the first battery, another portion of said body of oil being held as a pool above and inopen communication with the two batteries of tubes, and'ha-vin a vapor space above the same, and an ad itional portion held in areservoir in'open communication with thelower ends of the two "batteries of tubes, e'fi'ecting a cyclic circulation of the oil upwardly in the tubes of "the first battery of tubes, and downwardly in the tubes of the second battery, taking off the vapors from said vapor space, and condensing the same, and controlling the discharge of the vapors forimposing a pressure of the generated vapors upon the body of. oil under'treatrnent, substantially as described.

7. A process of converting heavy into lighter hydrocarbons which consists in cracking the oil under a pressure in excess of 50- pounds to the square inch, causing the oil to pass upwardly through vertical tubes seated in a furnace and thence to a vapor chamber, taking off the vapors from said vapor chamber and collecting and condens ing them, returning the unva orized oil from said chamber vertically ownwardly through a second set of tubes located in said furnace and thence to a reservoir located outside of the heating zone, returning the oil from the reservoir to the first set of vertical tubes and continuing said circulation durin the process. l v

8. process of converting heavy into lighter hydrocarbons which consists inc-racking the oil under a pressure in excess of 50 to pass upward y through vertical tubes square inch, causing the oil seated in a furnace and thence to a vapor I chamber, taking off the vapors fromi said vapor chamber and c ollectingfa dic0ndensing them, returning ,the 'unvaporized oil from said chamber to a reservoir located outside of theheating zone and returning the oil from the reservoir to said vertical,

tabes and continuing saidcirculation during the process.

[CARBON P; DUBBS.

MAM 

